CmdPal: Improve crash error message (#43340)

## Summary of the Pull Request

This PR localizes the message displayed when an unhandled exception
causes CmdPal to crash. It also resolves a regression from commit
a991a118dc, which disabled storing to the desktop but failed to
update the corresponding message.

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## PR Checklist

- [x] Related to: #41392
- [ ] **Communication:** I've discussed this with core contributors
already. If the work hasn't been agreed, this work might be rejected
- [ ] **Tests:** Added/updated and all pass
- [ ] **Localization:** All end-user-facing strings can be localized
- [ ] **Dev docs:** Added/updated
- [ ] **New binaries:** Added on the required places
- [ ] [JSON for
signing](https://github.com/microsoft/PowerToys/blob/main/.pipelines/ESRPSigning_core.json)
for new binaries
- [ ] [WXS for
installer](https://github.com/microsoft/PowerToys/blob/main/installer/PowerToysSetup/Product.wxs)
for new binaries and localization folder
- [ ] [YML for CI
pipeline](https://github.com/microsoft/PowerToys/blob/main/.pipelines/ci/templates/build-powertoys-steps.yml)
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- [ ] [YML for signed
pipeline](https://github.com/microsoft/PowerToys/blob/main/.pipelines/release.yml)
- [ ] **Documentation updated:** If checked, please file a pull request
on [our docs
repo](https://github.com/MicrosoftDocs/windows-uwp/tree/docs/hub/powertoys)
and link it here: #xxx

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## Detailed Description of the Pull Request / Additional comments

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## Validation Steps Performed

src/modules/cmdpal/Microsoft.CmdPal.UI/Helpers/GlobalErrorHandler.cs

@@ -51,10 +51,10 @@ internal sealed partial class GlobalErrorHandler
         // without its exception being observed. It is NOT raised immediately
         // when the Task faults; timing depends on GC finalization.
         e.SetObserved();
-        HandleException(e.Exception, Context.UnobservedTaskException, isRecoverable: true);
+        HandleException(e.Exception, Context.UnobservedTaskException);
     }
 
-    private void HandleException(Exception ex, Context context, bool isRecoverable = false)
+    private static void HandleException(Exception ex, Context context)
     {
         Logger.LogError($"Unhandled exception detected ({context})", ex);
 
@@ -70,10 +70,25 @@ internal sealed partial class GlobalErrorHandler
 
             StoreReport(report, storeOnDesktop: false);
 
+            string message;
+            string caption;
+            try
+            {
+                message = ResourceLoaderInstance.GetString("GlobalErrorHandler_CrashMessageBox_Message");
+                caption = ResourceLoaderInstance.GetString("GlobalErrorHandler_CrashMessageBox_Caption");
+            }
+            catch
+            {
+                // The resource loader may not be available if the exception occurred during startup.
+                // Fall back to hardcoded strings in that case.
+                message = "Command Palette has encountered a fatal error and must close.";
+                caption = "Command Palette - Fatal error";
+            }
+
             PInvoke.MessageBox(
                 HWND.Null,
-                "Command Palette has encountered a fatal error and must close.\n\nAn error report has been saved to your desktop.",
-                "Unhandled Error",
+                message,
+                caption,
                 MESSAGEBOX_STYLE.MB_ICONERROR);
         }
     }